What is Blowfish you ask? Blowfish is a programming language (well, an "in progress" programming language).
Right now, as far as "concrete code" is concerned, Blowfish is a lexer (tokenizer) and an AST builder.
This is really just the pet project of Michael Gilliland.
For further documentation see: http://www.youtube.com/watch?v=7HMts8iiZ3M